1. Technical Field
The present invention relates generally to food processing and associated equipment, and more particularly to an improved method and apparatus for the semi-continuous pressing of meat pieces.
2. Background Art
The flattening of meat products in the food processing industry is well known. For many years machines called ‘flatteners’ have been used in the meat industry to crush meat pieces to change the shape of the pieces for processing. Meat that is crushed to a reasonably even thickness cooks more evenly than does the same piece in a natural shape which may have thick sections and thin sections. In the case of standard flatteners the only objective is to create a piece of meat with a standard thickness. This process damages the meat fibers in the thick sections of the meat piece, and does nothing to the fibers in the thin sections. If a meat piece is crushed in a standard flattener and is marinated in a tumbler drum it typically splits or breaks apart into several smaller pieces.
This conventional type of flattener will not work at all when the meat pieces have bones in them. The bones do not allow the meat piece to be flattened, and when flattening is attempted in a conventional flattener the meat is stripped away from the bones and the bones are broken, resulting in unacceptable damage to the product.
It has been discovered that if meat pieces are pressed with a significant amount of force applied more or less evenly throughout the piece of meat, it will tenderize the meat piece and condition the meat fibers so that marinade will be absorbed into the meat fibers without the use of a vacuum. This pressing must be done in a manner where nearly the same force is applied to all parts of the meat piece, regardless of the shape of the meat and regardless of whether there is a bone in the meat. This type of pressing of the meat is not possible with a conventional flattener because the contact parts of the conventional flatteners are hard and inflexible.
To make an effective conditioning press a number of methods of pressing have been proposed. Running the meat pieces between two pliable rollers is one method that was tried. The problem with this method of pressing is that the thick parts of the meat or the bone would hang up at the entry point of the rollers and would not be pulled in between the rollers. Since part of the piece was in between the rollers but the thick parts of the pieces would not pull in, the rotating rollers would pull the meat pieces apart, causing significant damage to the pieces of meat.
Another method that was tried was to press the meat with a roller or flat pad that was actuated by air pressure. The theory of this concept was to control the force applied to the meat with air cylinders to reduce the damage to the meat. The problem with this system of actuating the press with air cylinders is threefold. First, the contact surfaces must be pliable in order to apply the same force onto all sections of the meat piece regardless of the thickness of each section, even if there are bones in the meat. Next, the pressure must be high enough to properly condition the meat fibers throughout all sections of the meat piece. Finally, the proper pressing pressure must be applied regardless of the number of meat pieces in the press at one time. This last requirement made air cylinder actuation unacceptable. Since the air in the cylinders is compressible, the force actually applied to each meat piece is inversely proportional to the number of pieces in the press at one time.
All types of methods of pressing with the press pads in direct contact with the meat pieces caused excessive damage to the meat. The friction between the press pads and the meat piece as the meat piece was deformed under pressure caused excessive damage to the surface of the meat piece. This damage was intermittent in that one piece would be undamaged while the piece beside it would be excessively damaged. Presumably the difference in damage was related to the difference in structural makeup of the pieces of meat.
United States Patent Application 20020012726 by Anders, et al. discloses a liquid infusion and tenderization process, apparatus, and product for treating food items having muscle protein. The inventive method continuously presses the food items in a pressing chamber having a plunger and trough arrangement, using a pliable material which conforms to and at least partially surrounds the food items when pressing, and/or infuses the food items with a treatment liquid preferably by impacting the food items while they are at least partially suspended in the solution.
In summary, conventional methods of pressing meat pieces are unacceptable in terms of muscle damage and/or inflexible or noncompliant force being applied to all sections of the meat piece.
The foregoing discussion reflects the current state of the art of which the present inventor is aware. Reference to, and discussion of, this information is intended to aid in discharging Applicant's acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that none of the prior art discloses, teaches, suggests, shows, or otherwise renders obvious, either singly or when considered in combination, the invention described and claimed herein.